Acoustic transducer module

ABSTRACT

A module ( 100, 200, 300, 400, 500, 600 ) may be electrically connected to a PCB ( 18 ) residing in a device ( 14 ) or may be joined to the device ( 14 ) to form a portion of the housing ( 16 ) of the device ( 14 ). The module includes a housing ( 102, 202, 302, 402, 502, 602 ) having at least one layer, a surface mountable component, such as a surface mountable acoustic transducer ( 110, 210, 310, 410, 510, 610 ) having a connecting surface ( 114, 214, 314, 414, 514, 614 ) disposed within the housing ( 102, 202, 302, 402, 502, 602 ), and at least one acoustic port ( 124, 224, 324, 424, 524, 624 ) formed on a surface of the housing ( 102, 202, 302, 402, 502, 602 ). The module ( 100, 200, 300, 400, 500, 600 ) may further include a secondary mounting structure ( 654 ) electrically connected to the connecting surface ( 114, 214, 314, 414, 514, 614 ) of the surface mountable acoustic transducer ( 110, 210, 310, 410, 510, 610 ). The acoustic port ( 124, 224, 324, 424, 524, 624 ) may include a layer of an environmental barrier ( 450, 550 ).

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent claims the benefit of U.S. Provisional Patent ApplicationNo. 60/450,569, filed Feb. 28, 2003 herein incorporated by reference inits entirety for all purposes.

TECHNICAL FIELD

This patent relates to transducer modules used in communication devices,audio devices or the like, and more particularly, tomicro-electromechanical systems (MEMS) miniature silicon condensermicrophone modules.

TECHNICAL BACKGROUND

Mobile communication technology advancements have progressed rapidly inrecent years. Consumers are increasingly using mobile communicationdevices such as cellular phones, web-enabled cellular telephones,Personal Digital Assistants (PDA), hand-held computers, laptops, tabletsor any other device types that are capable of communication over publicor private communication networks. The deployment of more cellularnetworks especially and the technological advancements in mobilecommunication technology have resulted in more consumers using mobilecommunications devices driving improvements in the manufacturingprocesses, power consumption, reception, fabrication, andminiaturization of the audio devices. As the size of mobilecommunication devices becomes smaller, ever-increasing demands areplaced upon improving the inherent performance of the miniaturetransducer modules that are utilized.

Generally speaking, conventional electret condenser microphones (ECM)have been used for communication devices such as cellular phones,web-enabled phones, Personal Digital Assistants (PDA), hand-heldcomputers, laptops, tablets or other such devices. In thesecommunication devices, such as cellular telephones, a connector memberelectrically connects an electret condenser microphone to a printedcircuit board fixed within a device housing. The connector may include agasket between the ECM and the outer housing that is formed with anaperture or port to provide an acoustic path from outside the housing tothe ECM. The final assembly of the ECM and the connector with gasketonto the PCB within the housing must be done either manually or withoff-line equipment resulting in considerable yield loss due to eitherpoor electrical connections or a poor (leaky) acoustic connection.Soldering of the ECM is not possible due to temperature limitations ofthe materials used to construct it.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cellular phone incorporating acondenser microphone module in accordance with the describedembodiments;

FIG. 2 is a partial cross-sectional view of the cellular phone of FIG.1;

FIGS. 3A-3B are cross-sectional views of a described embodiment of anacoustic transducer module;

FIGS. 4A-4B are cross-sectional views of another described embodiment ofan acoustic transducer module;

FIGS. 5A-5B are cross-sectional views of another described embodiment ofan acoustic transducer module;

FIGS. 6A-6C are cross-sectional views of another described embodiment ofan acoustic transducer module;

FIGS. 7A-7C are cross-sectional views of another described embodiment ofan acoustic transducer module; and

FIG. 8 is a cross-sectional view of another described embodiment of anacoustic transducer module.

DETAILED DESCRIPTION

While the present invention is susceptible to various modifications andalternative forms, certain embodiments are shown by way of example inthe drawings and these embodiments will be described in detail herein.It should be understood, however, that this disclosure is not intendedto limit the invention to the particular forms described, but to thecontrary, the invention is intended to cover all modifications,alternatives, and equivalents falling within the spirit and scope of theinvention defined by the appended claims.

Embodiments of the invention described herein overcome assembly andperformance problems associated with previous designs to provide asimple, efficient and economic way and method of manufacturing anacoustic transducer module, such as a microphone module for use withcommunications devices. The many features and advantages of theinvention include providing a reliable electrical connection and areliable, leak free, acoustic connection. In various embodiments, theinvention uses a micro-electromechanical system (MEMS) device, e.g., atransducer and/or silicon-based microphone for use with communicationdevices.

As will be appreciated from the following description of embodiments, anacoustic transducer module includes a housing and a surface mountedacoustic transducer disposed within the housing. The surface mountedacoustic transducer may have a surface for electrically coupling thesurface mounted acoustic transducer to a printed circuit board. Thesurface is exposed externally of the housing. An acoustic pathwaycouples the surface mounted acoustic transducer to an exterior surfaceof the housing.

The surface mounted acoustic transducer may be received within a cavityformed within the housing and secured therein, for example, bymechanical fasteners, friction and mutually engaging mechanicalelements. Alternatively, the surface mounted acoustic transducer issecured by bonding or in situ molded within the housing.

The housing may include a first housing member and a second housingmember. The first housing member may be an inner housing layer and thesecond housing member may be an outer housing layer. An intermediatelayer may be disposed between the first housing layer and the secondhousing layer. The first housing layer and the second housing layer mayeach be non-conductive and the intermediate layer may be a conductivelayer.

A barrier may be disposed within the acoustic pathway. The barrier maybe a polymeric material film or a sintered metal.

The housing may include a retaining structure adjacent the connectingsurface. The retaining structure may be sized to receive an extensionportion of a printed circuit board of an electronic device.

The housing may include a mounting structure. The mounting structure isconfigured to engage a complimentary mounting structure formed on anelectronic device for securing the acoustic transducer module to theelectronic device. A secondary mounting structure may also be providedto electrically couple the surface mounted acoustic transducer to anelectronic device.

The surface mounted acoustic transducer may be a miniature siliconcondenser microphone.

An electronic device may include a housing and a printed circuit boardsecured within the housing. An acoustic transducer housing is alsoprovided and a surface mounted acoustic transducer is disposed withinthe acoustic transducer housing. The surface mounted acoustic transducermay have a surface for electrically coupling the surface mountedacoustic transducer to the printed circuit board, the surface beingexposed externally of the acoustic transducer housing. At least oneacoustic pathway couples the surface mounted acoustic transducer to anexterior surface of the housing. The acoustic transducer housing issecured to the housing and surface being in contact with the printedcircuit board to electrically couple the surface mounted acoustictransducer to printed circuit board. The electronic device may be acellular telephone, a personal digital assistant, a pager, a laptopcomputer or a portable web browser. The acoustic transducer housing maybe bonded to, mechanically secured to or in situ molded within thehousing, and the acoustic transducer housing may have a surface forminga portion of a surface of the housing.

Referring to FIGS. 1-2, a silicon condenser microphone module is showngenerally at numeral 10. The module 10 is electrically connected to aprinted circuit board (PCB) 12 residing in a hand-held wirelesscommunication device 14, such as a cellular phone. Of course the module10 may be adapted for use in virtually any other type of electronicdevice, including web-enabled phones, personal digital assistant (PDA)devices, other types of portable computing and Internet accessappliances and devices, and the like, that may also be capable ofcommunication over public or private communication networks. Asexplained in greater detail below, the module 10 may be mated with thedevice 14. Alternately, the module 10 may be joined to the device 14 toform a portion of its outer housing 16.

Referring now to FIGS. 3A-3B a module 100 in accordance with a describedembodiment of the invention can be used in a communication device,including devices similar to the cellular phone 14 illustrated inFIG. 1. The module 100 may include a housing 102 including a top housingsection 104 and a bottom housing section 106. The top housing section104 and the bottom housing section 106 may be joined together bymechanical fastening, crimping, welding or adhesive bonding, forinstance. The housing 102 is shown to have at least one layer; however,the housing 102 may utilize alternating layers of conductive and/ornon-conductive materials and such embodiment will be discussed ingreater detail. In the embodiment shown, the housing 102 is made ofpolymeric material such as molded plastic material.

The module 100 further includes a surface mountable component 110, asubstrate (not shown), and a retainer structure 112. The surfacemountable component (SMC) 110 may include a micro-electromechanicalsystem (MEMS) device, e.g. a transducer or silicon-based microphone suchas the silicon condenser microphone disclosed in U.S. Pat. No.5,870,482; U.S. patent application Ser. No. 09/886,754; InternationalPatent Application PCT/US0148462; and/or U.S. patent application Ser.No. 10/238,256, the disclosures of which are herein incorporated byreference in their entirely for all purposes. In the embodiment shown,the SMC 110 is a MEMS based, miniature silicon condenser microphone. TheSMC 110 may be molded within the housing 102 or fit or molded within theretainer structure 112 formed within the housing 102.

The SMC 110 includes a connecting surface 114 for electricallyconnecting with a printed circuit board (PCB) 12 within thecommunication device or to otherwise electrically couple the SMC 110 tothe communication device. The connecting surface 114 can be located onan upper surface 116, a side surface 118, or a bottom surface 120 of theSMC 110. The connecting surface 114 may be electrically coupled to thePCB via a soldering process; however, it will be understood by thoseskilled in the art that any form of electrical connection would suffice,including conductive adhesive, contacts, spring-loaded contacts, plugs,and the like. The module 100 may further include a secondary mountingstructure that is electrically coupled to the connecting surface 114 andsuch embodiment will be discussed in greater detail. In the embodimentshown, the connecting surface 114 is located on the side surface 118 ofthe SMC 110 for electrically coupling the SMC 110 with the PCB 12 withinthe device 14.

At least one aperture or acoustic port, three are illustrated as ports124 a, 124 b and 124 c, is introduced on the surface of the housing 102to allow acoustic waves to enter. For simplicity, when referring to theone or more acoustic ports reference will be made to acoustic port 124with the understanding the one or more such ports may be provided.Multiple acoustic ports provide a directional sensitivity capability inthe SMC 110. The acoustic port 124 can be formed on the upper surface126, side surface 128 or bottom surface 130 of the housing 102, or inmultiple locations on these surfaces. In the embodiment shown, the firstacoustic port 124 a is located on the upper surface 126, the secondacoustic port 124 b is located on the bottom surface 130, and the thirdacoustic port 124 c is located on the side surface 128 to providedirectional characteristics, i.e., omni-directional, bi-directional, oruni-directional sensitivity in the SMC 110.

The acoustic port 124 may be formed by a number of methods, includingdrilling through the housing 102 to form an acoustic pathway to the SMC110 or molding the acoustic port 124 into the housing 102.Alternatively, a port may be formed, such as by drilling, completelythrough the housing 102, the device PCB and outer housing to allowacoustic energy to be coupled to the SMC 110.

The module 100 is capable of withstanding relatively high temperaturesincluding those associated with various plastic molding processes. Themodule 100 may therefore be mounted within or mated to the device 14during a plastic molding process used to produce the device housing 16.Doing so provides the advantages of reduced overall size of the devicewhile maintaining good electroacoustic performance such as sensitivity,noise, stability, compactness, robustness, and insensitivity toelectromagnetic interference (EMI) and other external and environmentalconditions (including shock and debris).

As shown, the module 100 is electrically connected such as by solderingto the PCB 12 within the device 14. Alternately, the module 100 may bemechanically or frictionally joined with the housing 16 of the device14. Alternative methods such as fasteners, frictional connectors, snapfit, tongue and groove assemblies, that may or may not be formed as aportion of the external surface or outer housing 16 of the device 14,may be used to secure the module 100 to the device 14 by engagingcorresponding structures or surfaces of the housing 102. It will befurther understood by those skilled in the art that bonding and similarforms of joining, such as epoxy, tape and the like, may be used. Thehousing 102 of the module 100 may be colored and/or textured with asmooth polished surface including beveled edges, dimples, or the like tomatch the external surface or outer housing 16 of the device 14.

Referring now to FIGS. 4A-4B a module 200 in accordance with a describedembodiment of the invention can be used in communication device,including devices similar to the device 14 illustrated in FIG. 1. Themodule 200 is similar in construction and function as the module 100illustrated in FIGS. 3A and 3B, and like elements are referred to usinglike reference numerals wherein, for example, 100 and 102 correspond to200 and 202, respectively. The module 200 may include a housing 202including a top housing section 204 and a bottom housing section 206.The top housing section 204 and the bottom housing section 206 may bejoined together by mechanical fastener, crimping, welding or adhesivebonding, for instance. The housing 202 is shown to have at least onelayer 208; however, the housing 202 may utilize alternating layers ofconductive and/or non-conductive materials and such embodiment will bediscussed in greater detail. In the embodiment shown, the housing 202 ismade of polymeric material such as molded plastic material.

The module 200 further includes a surface mountable component 210, asubstrate (not shown) and a retainer structure 212. The surfacemountable component (SMC) 210 may include a micro-electromechanicalsystem (MEMS) device, e.g. a transducer or silicon-based microphone suchas the silicon condenser microphone disclosed in afore-mentioned U.S.Pat. No. 5,870,482; U.S. patent application Ser. No. 09/886,754;International Patent Application PCT/US0148462; and/or U.S. patentapplication Ser. No. 10/238,256. In the embodiment shown, the SMC 210 isa MEMS based, miniature silicon condenser microphone. The SMC 210 may bemolded within the housing 202 or fit or molded within the retainerstructure 212 formed within the housing 202.

The SMC 210 includes a connecting surface 214 for electricallyconnecting with a printed circuit board (PCB) 12 within thecommunication device or to otherwise electrically couple the SMC 210 tothe communication device. The connecting surface 214 can be located onan upper surface 216, a side surface 218, or a bottom surface 220 of theSMC 210. The connecting surface 214 may be electrically coupled to thePCB via a soldering process; however, it will be understood by thoseskilled in the art that any form of electrical connection would suffice,including conductive adhesive, contacts, spring-loaded contacts, plugs,and the like. The module 200 may further include a secondary mountingstructure that is electrically coupled to the connecting surface 214 andsuch embodiment will be discussed in greater detail. In the embodimentshown, the connecting surface 214 is located on the bottom surface 220of the SMC 210 for electrically coupling the SMC 210 with the PCB 12within the device 14.

At least one aperture or acoustic port, two are illustrated as ports 224a and 224 b, is introduced on the surface of the housing 202 to allowacoustic waves to enter. For simplicity, when referring to the one ormore acoustic ports reference will be made to acoustic port 224 with theunderstanding the one or more such ports may be provided. Multipleacoustic ports provide a directional sensitivity capability in the SMC210. The acoustic port 224 can be formed on the upper surface 226, sidesurface 228 or bottom surface 230 of the housing 202, or in multiplelocations on these surfaces. In the embodiment shown, the first acousticport 224 a is located on the upper surface 226 and the second acousticport 224 b is located on the bottom surface 230 to provide directionalcharacteristics, i.e., omni-directional, bi-directional, oruni-directional sensitivity in the SMC 210.

The acoustic port 224 may be formed by a number of methods, includingdrilling or molding through the housing 202 to form an acoustic pathwayto the SMC 210. Alternatively, a port may be formed, such as bydrilling, completely through the housing 202, the device PCB and outerhousing to allow acoustic energy to be coupled to the SMC 210.

The module 200 is capable of withstanding relatively high temperaturesincluding those associated with various plastic molding processes. Themodule 200 may therefore be mounted within or mated to the device duringa plastic molding process used to produce the device housing. Doing soprovides the advantages of reduced overall size of the device whilemaintaining good electro-acoustic performance such as sensitivity,noise, stability, compactness, robustness, and insensitivity toelectromagnetic interference (EMI) and other external and environmentalconditions (including shock and debris).

As shown in FIG. 4A, the module 200 is electrically connected such as bysoldering to the PCB 12 within the device 14. Alternately, FIG. 4B showsthe module 200 may be mechanically or frictionally joined within theretaining structure 212 formed within the housing 16 of the device 14.In the illustrated embodiment, an extension portion 18 of the PCB 12extends into and is locked within a relief structure 225. A surface 20of the PCB 12 is pressed into contact with the connection surface 214electrically coupling the module 200 to the PCB 12. Alternative methodssuch as fasteners, frictional connectors, snap fit, tongue and grooveassemblies, that may or may not be formed as a portion of the externalsurface or outer housing 16 of the device 14, may be used to secure themodule 200 to the device. It will be further understood by those skilledin the art that bonding and similar forms of joining, such as epoxy,tape and the like, may be used. The housing 202 of the module 200 may becolored and/or textured with a smooth polished surface including abeveled edge, dimples, or the like to match the external surface orouter housing 16 of the device 14.

As shown in FIG. 4A, the combination of the housing 202, the PCB 12, andthe housing 16 of the device 14 creates the second acoustic port 224 band are in alignment with the SMC 210 for delivering acoustic energy tothe SMC 210. The first acoustic port 224 a located on the upper surface216 of the housing 202 and is acoustically coupled to the SMC 210.

The module 200 may be mounted within or mated to the device 14 duringthe plastic molding process used to form the device housing 16 to reducethe overall size of the device 14 and yet to maintain goodelectro-acoustic performance such as sensitivity, noise, stability,compactness, robustness, and insensitivity to electromagneticinterference (EMI) and other external and environmental conditions(including shock and debris).

Referring now to FIGS. 5A-5B a module 300 in accordance with a describedembodiment of the invention can be used in a communication device,including devices similar to the device 14 illustrated in FIG. 1. Themodule 300 is similar in construction and function as the module 100illustrated in FIGS. 3A and 3B, and like elements are referred to usinglike reference numerals wherein, for example, 100 and 102 correspond to300 and 302, respectively.

The SCM 310 may be affixed to the housing 302 by providing a layer ofepoxy 332 such as a B-staged epoxy around the SMC 310 to form a gasketseal; however, it will be understood by those skilled in the art thatother methods for affixing the SMC 310 are possible. In the embodimentshown, the gasket 332 is formed at least to prevent leakage of acousticwaves from the acoustic pathway coupling the SMC 310 to the outside ofthe housing 302.

At least one aperture or acoustic port, three are illustrated as ports324 a, 324 b and 324 c in FIG. 5A and two 324 a and 324 b areillustrated in FIG. 5 b, is introduced on the surface of the housing 302to allow acoustic waves to enter. For simplicity, when referring to theone or more acoustic ports reference will be made to acoustic port 324with the understanding the one or more such ports may be provided.Multiple acoustic ports provide a directional sensitivity capability inthe SMC 310. The acoustic port 324 can be formed on the upper surface326, side surface 328 or bottom surface 330 of the housing 302, or inmultiple locations on these surfaces. In the embodiment shown, the firstacoustic port 324 a is located on the upper surface 326, the secondacoustic port 324 b is located on the bottom surface 330, and the thirdacoustic port 324 c is located on the side surface 328 to providedirectional characteristics, i.e., omni-directional, bi-directional, oruni-directional sensitivity in the SMC 310.

The acoustic port 324 may be formed by a number of methods, includingdrilling or molding through the housing 302 to form an acoustic pathwayto the SMC 310. Alternatively, a port may be formed, such as bydrilling, through the housing 302, the device PCB and outer housing toallow acoustic energy to be coupled to the SMC 310.

The module 300 may be electrically connected such as by soldering to thePCB 12 within the device 14. Alternately, FIG. 5B shows that the module300 may be mechanically or frictionally joined within a retainingstructure 312. Alternative methods such as fasteners, frictionalconnectors, snap fit, tongue and groove assemblies, that may or may notbe formed as a portion of the external surface or outer housing 16 ofthe device 14, may be used to secure the module 300 to the device. Itwill be further understood by those skilled in the art that boding andsimilar forms of joining, such as epoxy, tape and the like, may be used.The housing 302 of the module 300 may be colored and/or textured with asmooth polished surface including a beveled edge, dimples, or the liketo match the external surface or outer housing 16 of the device 14.

Referring now to FIGS. 6A-6C a module 400 in accordance with a describedembodiment of the invention can be used in communication device,including devices similar to the device 14 illustrated in FIG. 1. Themodule 400 is similar in construction and function as the module 100illustrated in FIGS. 3A and 3B, and like elements are referred to usinglike reference numerals wherein, for example, 100 and 102 correspond to400 and 402, respectively.

The housing 402 is shown to have at least two layers 432 and 434,wherein layer 432 is an inner layer and layer 434 is an outer layer. Theinner layer 432 is attached to the outer layer 434 for example, bybonding with adhesive, compression, or mechanical attachment. In oneexample, the inner layer 432 is made of polymeric material such as amolded plastic material and the outer layer 434 is made of polymericmaterial such as a molded plastic material that may be the same as ordifferent than the polymeric material used to form the inner layer 432.

As illustrated in FIG. 6C, the housing 402 is made of a first layer 440,a second layer 442, and a third layer 444. The first layer 440 isattached on a surface 446 of the second layer 442 for example, bybonding with adhesive, compression, or mechanical attachment. The thirdlayer 444 is attached on a surface 448 of the second layer 442 forexample, by bonding with adhesive, compression, or mechanicalattachment. In one example, the first and third layers 440 and 444 aremade of polymeric material such as a molded plastic material and thesecond layer 442 is made of conductive material such as copper. Thesecond layer 442 may be formed between the first layer 440 and the thirdlayer 442 to protect the SMC 400 within the housing 400 againstelectromagnetic interference and the like.

The SMC 410 includes a connecting surface 414 for electricallyconnecting with a printed circuit board (PCB) with the device or tootherwise electrically couple the SMC 410 to the device. The connectingsurface 414 can be located on an upper surface 416, a side surface 418,or a bottom surface 420 of the SMC 410. The connecting surface 414 maybe electrically coupled to the PCB via a soldering process; however, itwill be understood by those skilled in the art that any form ofelectrical connection would suffice, including conductive adhesive,contacts, spring-loaded contacts, plugs, and the like. In the embodimentshown, the connecting surface 414 is located on the side surface 418 ofthe SMC 410 for electrically coupling the SMC 410 with the PCB withinthe device.

At least one aperture or acoustic port, three are illustrated as ports424 a, 424 b and 424 c, is introduced on the surface of the housing 402to allow acoustic waves to enter. For simplicity, when referring to theone or more acoustic ports reference will be made to acoustic port 424with the understanding the one or more such ports may be provided.Multiple acoustic ports provide a directional sensitivity capability inthe SMC 410. The acoustic port 424 can be formed on the upper surface416, side surface 418 or bottom surface 420 of the housing 402, or inmultiple locations on these surfaces. In the embodiment shown, the firstacoustic port 424 a is located on the upper surface 416, the secondacoustic port 424 b is located on the bottom surface 420, and the thirdacoustic port 424 c is located on the side surface 418 to providedirectional characteristics, i.e., omni-directional, bi-directional, oruni-directional sensitivity in the SMC 410.

The acoustic port 424 may be formed by a number of methods, includingdrilling or molding through the housing 402 to form an acoustic pathwayto the SMC 410. Alternatively, a port may be formed, such as bydrilling, through the housing 402, the device PCB and outer housing toallow acoustic energy to be coupled to the SMC 410.

An environmental barrier layer 450 that may be made of a flat plasticsheet, e.g., polymeric material film such as polytetrafluorethylene(PTFE) or a sintered metal is adhered to cover the acoustic ports 424 a,424 b, 424 c to prevent debris from entering the module 400 and damagingthe SMC 410 and the retaining structure 412 disposed within the housing402. The environmental barrier layer 450 may further be selected to haveacoustic properties, such as acoustic resistive properties, to improvethe frequency response, create delay and provide directional response.

Referring now to FIGS. 7A-7B a module 500 in accordance with a describedembodiment of the invention can be used in communication device,including devices similar to the device 14 illustrated in FIG. 1. Themodule 500 is similar in construction and function as the module 100illustrated in FIGS. 3A and 3B, and like elements are referred to usinglike reference numerals wherein, for example, 100 and 102 correspond to500 and 502, respectively.

The housing 502 is made of an inner layer 532 and at least one outerlayer 534. The inner layer 532 is attached to the outer layer 534 forexample, by bonding with adhesive, compression, or mechanicalattachment. In one example, the inner layer 532 is made of polymericmaterial such as a molded plastic material and the outer layer 534 ismade of polymeric material such as a molded plastic material that may bethe same as or different than the inner layer 532. Referring now to FIG.7C, the housing 502 is made of a first layer 540, a second layer 542,and a third layer 544. The first layer 540 is attached on a surface 546of the second layer 542 for example, by bonding with adhesive,compression, or mechanical attachment. The third layer 544 is attachedon a surface 548 of the second layer 542 for example, by bonding withadhesive, compression, or mechanical attachment. The second layer 542may be molded in situ between the first layer 540 and the third layer544. In one example, the first and third layers 540 and 544 are made ofpolymeric material such as a molded plastic material and the secondlayer 542 is made of conductive material such as copper. The secondlayer 542 is formed between the first layer 540 and the third layer 544to protect the SMC 510 within the housing 502 against electromagneticinterference and the like.

The SMC 510 may include a connecting surface 514 for electricallyconnecting with a printed circuit board (PCB) 12 of the device 14. Theconnecting surface 514 can be located on an upper surface 516, a sidesurface 518 or a bottom surface 520 of the SMC 510. The connectingsurface 514 may be attached to the PCB via a soldering process; however,it will be understood by those skilled in the art that any form ofelectrical connection would suffice, including contacts, spring-loadedcontacts, plugs, and the like. The module 500 may include a reliefstructure 525 adapted to receive an extension portion 18 of the PCB 12for mechanically securing and electrically coupling the module 500 tothe PCB 12. In the embodiment shown, the connecting surface 514 islocated on the bottom surface 520 of the SMC 510 for electricallyconnecting with the PCB 12 of the device 14.

At least one aperture or acoustic port, two are illustrated as ports 524a and 524 b, is introduced on the surface of the housing 502 to allowacoustic waves to enter. For simplicity, when referring to the one ormore acoustic ports reference will be made to acoustic port 524 with theunderstanding the one or more such ports may be provided. Multipleacoustic ports provide a directional sensitivity capability in the SMC510. The acoustic port 524 can be formed on the upper surface 526, sidesurface 528 or bottom surface 530 of the housing 502, or in multiplelocations on these surfaces. In the embodiment shown, the first acousticport 524 a is located on the upper surface 526 and the second acousticport 524 b is located on the bottom surface 530 to provide directionalcharacteristics, i.e., omni-directional, bi-directional, oruni-directional sensitivity in the SMC 410.

The acoustic port 524 may be formed by a number of methods, includingdrilling for molding through the housing 502 to form an acoustic pathwayto the SMC 510 (FIGS. 7A-7B). Alternatively, a port may be formed, suchas by drilling, through the housing 502, the device PCB and outerhousing to allow acoustic energy to be coupled to the SMC 510.

An environmental barrier layer 550 that may be made of polymericmaterial film such as polytetrafluorethylene (PTFE) or a sintered metalis adhered to cover the acoustic ports 524 a and 524 b to prevent debrisfrom entering the module 500 and damaging the SMC 510 and the receiver512 disposed within the housing 502. The environmental barrier layer 550may selected to have acoustic properties to further improve thefrequency response, create delay and provide directional response.

Referring now to FIG. 8 a module 600 in accordance with a describedembodiment of the invention can be used in communication device,including devices similar to the device 14 illustrated in FIG. 1. Themodule 600 is similar in construction and function as the module 100illustrated in FIGS. 3A and 3B, and like elements are referred to usinglike reference numerals wherein, for example, 100 and 102 correspond to600 and 602, respectively. The module 600 may further include asecondary mounting structure 654 that is electrically connected to theconnecting surface 614 of the SMC 610. The secondary mounting structure654 may be a flex circuit, lead frame, or the like, for instance. Thesecondary mounting structure 654 may or may not be molded within thehousing 602. In this example, the secondary mounting structure 654 isintroduced to allow the SMC 610 to be mounted or molded within thehousing 602 in a variety of orientations relative to the PCB 18 disposedwithin the device 14.

At least one aperture or one acoustic port, one illustrated as port 624a, is introduced on the surface of the housing 602 to couple acousticwaves to SMC 610. The acoustic port 624 a can be formed on the uppersurface 626, the side surface 628 or the bottom surface 630 of thehousing 602, or in multiple locations on the upper, bottom and/or sidesurfaces of the housing 602. In the embodiment shown, the first acousticport 624 a is located on the side surface 628 of the housing 602.

The module 600 may be mounted or mated within the device 14 during theplastic molding process used to form the housing 602 to reduce theoverall size of the device 14 and yet maintain good electro-acousticperformance such as sensitivity, noise, stability, compactness,robustness, and insensitivity to electromagnetic interference (EMI) andother external and environmental conditions (including shock anddebris). However, it will be understood by those skilled in the art thatany form of electrical connection would suffice.

A device constructed in accordance with one or more of the describedembodiments enjoy many advantages over the known devices. For example, amodule, such as module 100, 200, 300, 400, 500 or 600 may be mounted toa PCB disposed within a housing of the device or may be a plug-in typeunit, for instance. The module may be adapted for use in virtually anytype of electronic device and especially electronic communicationdevices such a cellular telephones, personal digital assistants, and thelike.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention unless otherwise claimed. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention. Itshould be understood that the illustrated embodiments are exemplaryonly, and should not be taken as limiting the scope of the invention.

1. An acoustic transducer module comprising: a housing; a surfacemountable acoustic transducer disposed within the housing, the surfacemountable acoustic transducer having a connecting surface configured toengage a retaining structure formed as a portion of the housing adjacentthe connecting surface, a relief structure within the housing having asize to receive an extension portion of a printed circuit board of anelectronic device; and at least one acoustic pathway coupling a surfaceof the surface mountable acoustic transducer to an exterior portion ofthe housing.
 2. The acoustic transducer module of claim 1, wherein thesurface mountable acoustic transducer is received within a chamberformed within the housing and secured therein.
 3. The acoustictransducer module of claim 2, wherein the surface mountable acoustictransducer is secured by one of: mechanical fasteners, friction andmutually engaging mechanical element.
 4. The acoustic transducer moduleof claim 2, wherein the surface mountable acoustic transducer is securedby bonding.
 5. The acoustic transducer module of claim 1, wherein thesurface mountable acoustic transducer is in situ molded within thehousing.
 6. The acoustic transducer module of claim 1, wherein thehousing comprises a first housing member and a second housing member. 7.The acoustic transducer module of claim 6, wherein the first housingmember comprises an inner housing layer and the second housing membercomprises an outer housing layer.
 8. The acoustic transducer module ofclaim 7, comprising an intermediate layer disposed between the firsthousing layer and the second housing layer.
 9. The acoustic transducermodule of claim 8, wherein the first housing layer and the secondhousing layer are each non-conductive and the intermediate layercomprises a conductive layer.
 10. The acoustic transducer module ofclaim 1, comprising a barrier disposed within the acoustic pathway. 11.The acoustic transducer module of claim 10, wherein the barriercomprises one of a polymeric material film and a sintered metal.
 12. Theacoustic transducer module of claim 1, wherein the surface mountedacoustic transducer comprises a miniature silicon condenser microphone.13. The acoustic transducer module of claim 1, wherein an outer surfaceof the housing is aesthetically similar to an outer surface of anelectronic device to which the acoustic transducer module is to becoupled.
 14. An acoustic transducer module comprising: a housing; asurface mountable acoustic transducer disposed within the housing, thesurface mountable acoustic transducer having a surface for electricallycoupling the surface mounted acoustic transducer to a printed circuitboard; and at least one acoustic pathway for delivering acoustic energyand acoustically coupling a surface of the surface mountable acoustictransducer to an exterior portion of the housing; wherein the housingcomprises a retaining structure adjacent the connecting surface, theretaining structure sized to receive an extension portion of a printedcircuit board of an electronic device.